Eyepiece for magnifying instruments.



J. N. ARRIAGA. EYEPIEUE POR MAGNIFYING INSTRUMENTS.

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APPLIOATOI FILED HOY. 2. 1900.

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"v1 TT ORNE YS J. N. ARRIAGA. zumos ron mammina INSTRUMENTS.

APPLIOATIOI FILED RDV. 2, 1909.

967,143. Patented Aug. 9, 1910.

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f ATTORNE V8 7%@ E @Wf JUAN' NEPOMUCEN'O ARBIAG-A, 0F MEXIICO, MEXICO.

EYEPIECE FOR MAGNIFYING INSTRUMENTS.

Specication of Letters Patent.

Patented Aug. 9, 1910.

Continuation of application Serial No. 420,706, led March 12, 1908. Thisapplication filed November 2, 1909. Serial No. 525,858.

To all whom 'it may concern:

Be it known that I, JUAN N. ARRIAGA, a citizen of the Republic ofMexico, and a resident of Mexico city, Mexico, have invented a new andImproved Eyepiece for Magnifying Instruments, of which the following` isa full, clear, and exact description.

This invention, heretofore described in an a plication filed March 12,1908, Serial umber 420,706, of which the present application is acontinuation, relates to an eyepiece for magnifying instruments, such asmicroscopes, telescopes, field glasses, opera glasses, etc.

The object of the invention is to produce an eye-piece of improvedconstruction which will operate to increase the magnifying power of theinstrument, and increase, also, its range and capacity for magnifying.

The invention consists in the construction and 'combination of parts tobe more fully described hereinafter and particularly set forth in theclaims.

Reference is to be had to the accompanying drawings forming a part ofthis specification, in which similar characters of reference indicatecorresponding parts in all the figures.

Figure 1 is a longitudinal section through an eye-piece embodying myinvention, and

adapted for use with an astronomical telescope or microscope; Fig. 2 isa similar View, but showing a modified form adapting the device for useas a terrestrial telescope, a field telescope, or field glass; Fig. 3 isa diagram illustrating the Inode of operation of a single divergent lenswhen used according to this invention; and Fig. 4 is also a diagrammaticview showing the manner in which the size of the image is controlled bymeans of two divergent lenses.

Referring more particularly to the parts, and especially to Fig. 1, lrepresents the barrel or body of the eye-piece, which is formed with adouble wall, as shown, so that an outer wall 2 is formed, and an innerwall or cylinder 3. In this way an annular guiding space is formedbetween the walls, and in this guiding space there is mounted a slidingsleeve 4, which is also of tubular form. This sleeve normally telescopeswith the body of the eye-piece, as indicated in full lines in Fig. 1.The lower end of the sleeve which projects from the body of theeye-piece is provided with a centrally disposed lens 5, which is doubleconcave, as shown. This lens does not completely fill the bore of thesleeve, but is of reduced diameter, as shown, being held in position bya suitable ring or thimble 6 which makes a threaded engagement with thebore of the sleeve, as shown. On the end of the sleeve beyond this lens,I provide a removable diaphragm 7 having an opening 8 of reduceddiameter, which controls the amount of light passing into the eye-piece.

At the upper end of the barrel 1, that is, at the end to which the eyeis applied in using the instrument, a plano convex lens 9 is attached,and over this lens there is seated an eye-cap 10 having an opening 11which uncovers the lens 9, as shown. Within the barrel or body 1, andnear the middle point thereof, as shown, there is mounted a concavoconvex lens 12, the said lens being held in position by a removable ring13 which is threaded in the barrel. Above this lens 12 there is aremovable diaphragm 14 having an opening l5 through which the lightpasses, and below the lens 12 a diaphragm 16 is formed in the barrel,this latter diaphragm having a similar opening 17 to pass the light. Thelenses 9 and 12 are such as are commonly used in telescopes, microscopesand similar optical instruments. The image produced by the objectivelens is formed at the usual point, just below the diaphragm 16.

In the lower end of the body 1 I provide a double concave lens 18, whichis exactly similar to the lens 5, and held in position by means of aring or spider 19 which screws into the lower end of the barrel 1.

It should be understood that the eye-piece constructed as described, isused in connection with a telescope, microscope or similar opticalinstrument having an object glass and any usual construction andarrangement of magnifying lenses. In using the eye-piece, the sleeve 4is adjusted in or out so as to regulate the distance between the movabledouble concave lens 5 and the fixed double concave lens 18. It will befound that the position of the lens 5 with respect to the lens 18, aectsthe size of the image produced in the eye, and that the farther apartthese lenses are, the larger will this image appear. Therefore, themovable double concave lens not only affords means for increasing themagnifying power, but also uuu-.untill affords means for regulating thedegree of magnification or capacity of the instrument, giving it agreater range of diameters of magnifying power.

Referring now to Fig. 2, I shall describe the eye-piece as constructedfor use with a terrestrial instrument. With this instrument, the barrel20 is provided with a double wall 21 only in the lower or outer portionthereof. Near the eye-cap 22 which is attached to the inner or upper endof the barrel, the usual achromatic lenses 23 and 24 are provided. Belowthe lens 24 a diaphragm 25 is formed in the barrel, with an opening topermit the passage of the light, and a similar diaphragm 26 is formed atabout the middle of the barrel. In the interior of the lower portion ofthe barrel an inner tube or inner wall 27 is fixed. In the upper orinner end of this inner tube an achromatic lens 28 is mounted, and nearthe middle of the inner tube a similar lens 29 is mounted. These lenses28 and 29 have the effect of reversing the image which is formed throughthem, so that an upright image will be seen by the observer. In thelower end of the inner tube 27 a diaphragm 30 is provided, having asmall opening to pass the light, as shown, and below this opening, inthe eXtreme end of the inner tube, an achromatic double concave lens 31is removably mounted. In the guide space in the double wall of the lowerend of the barrel, a sliding sleeve 32 is mounted, which is similar tothe sleeve 4, and in the lower end of this sleeve a double concave lens33 is mounted, the said lens being in all respects similar to the lens31 just above it. The lower end of the sleeve 32 is provided with asuitable cap 34 having an opening 35 through which the light passes. Thesleeve 32 is adapted to be drawn out as indicated in the dotted lines,so as to regulate the distance between the two lenses 31 and 33. In thisway the size of the image which the observer sees, may be nicelyregulated, and at the same time it is magnified. The inner faces of thewalls of the sleeves 4 and 32 are made black, also the inner face of thebodies of the eye-pieces, so that no light is reflected from the sidewalls of the instrument.

It should be understood that the eye-piece shown in Fig. 2 is used inthe same manner as the eye-piece shown in Fig. 1, but it is used withterrestrial instruments only.

Although I have shown double concave lenses in the illustrations, itshould be understood that I do not limit myself to this particular form,but I may use plano-concave lenses, meniscus lenses, and divergentconcavo-convex lenses; that is, I may use any divergent lens.

The manner in which the divergent lens 18 operates to enlarge the imageis clearly illustrated in the diagram, Fig. 3. In this diagram theoperation of a single divergent v lens in enlarging the image isillustrated, and in Fig. -t the effect of a second lens of the samekind, employed for the same general purpose, is illustrated. In Fig. 3,O represents the objective lens before which the object represented bythe line A-B is placed; if the divergent lens 18 were omitted, an imageof the object A, B would be formed at a, b in an inverted position.However, as the luminous rays pass through the lens 18, the convergenceof the rays which are united at any point of the image, is decreased sothat an enlarged image a2, b2 will be formed nearer to the eye, asindicated. This image will be displaced slightly to the rear of thenormal plane or focus where the image would have been formed in theabsence of the lens 18. Now if the lens 18 were absent, the image a,would appear tothe eye looking through the eye-piece, as enlarged andlocated at a, b. In order to bring the ima e a2, b2 into the plane ofthe image a, b', 1t would simply be necessary to move the instrumentaway from the object A, B slightly to some such position as thatindicated by the line c, d. In other words, the relative position of theobject is changed to advance the image a2, b2 to the point a3, b3. Inthis way the lens 18 operates to produce an enlarged image a3, b3, andthis enlarged image is in the plane of the image a', b; as seen throughthe eye-piece the image a3, b3 appears as an enlarged virtual imageindicated by the line at, b4. Thus the magnifying power of theinstrument is greatly increased.

Referring to Fig. 4, 18 represents the fixed divergent lens, while 5represents the movable divergent lens. The movable lens evidently willact upon the luminous rays to diverge them before rea ching the lens 18,and the effect of this divergence is greater or less, depending uponwhether the lens recedes from or approaches the lens 18, that is, thediverging effect of the lens is greater when the lens 5 is remote fromthe lens 18, and it is less when the lenses are near to `each other.

Vith an instrument constructed as described, it will therefore beevident that the presence of the fixed divergentlens just before thefocal point of the lens 12 will form a greatly enlarged image of theobject, and the size of this image may be controlled b means of themovable divergent lens before the fixed divergent lens. In this way theinstrument is given great power and great range.

Having thus described my invention, I claim as new and desire to secureby Letters Patent:

1. An eye-piece having a convex lens in combination with a divergentlens placed immediately before the focus of said convex 5 88. OPTICS,

vergence of the luminous ra s and formin an enlarged image, and a seconddiver ent lens disposed before said first divergent ens, one of saiddivergent lenses being movable with respect to the other whereby saidsecond lens may increase or decrease the size of the image formed.

3. An eye-piece having a convergent lens,

and a divergent lens placed immediately before the focus point thereof,to increase the size of the image formed, and a second divergent lensmovabl)7 mounted before said first divergent lens, adapted to recedethere- 20 from or approach to vary the size of the image formed.

1n testimony whereof I have signed my name to this specification in thepresence of two subscribing Witnesses.

JUAN NEPOMUCENO ARRIAGA.

Witnesses:

FELIX M. ALCEMEUX, YLDEroNso F. ORELLEMA.

